<template>
  <div>
    <div class="shopcart">
      <div class="content" @click="toggleList">
        <div class="content-left">
          <div class="logo-wrapper">
            <div class="logo" :class="{'highlight':totalCount>0}">
              <i class="icon-shopping_cart" :class="{'highlight':totalCount>0}"></i>
            </div>
            <div class="num" v-show="totalCount>0">{{totalCount}}</div>
          </div>
          <div class="price" :class="{'highlight':totalPrice>0}">￥{{totalPrice}}</div>
          <div class="desc">另需配送费￥{{deliveryPrice}}元</div>
        </div>
        <div class="content-right" @click.stop.prevent="pay">
          <div class="pay" :class="payClass">{{payDesc}}</div>
        </div>
      </div>
      <div class="ball-container">
        <template v-for="ball in balls">
          <transition
            name="drop"
            v-on:before-enter="beforeEnter"
            v-on:enter="enter"
            v-on:after-enter="afterEnter"
            :key="ball.__ob__.dep.id"
          >
            <div class="ball" v-show="ball.show">
              <div class="inner inner-hook"></div>
            </div>
          </transition>
        </template>
      </div>
      <transition name="fold">
        <div class="shopcart-list" v-show="listShow">
          <div class="list-header">
            <h1 class="title">购物车</h1>
            <span class="empty" @click="empty">清空</span>
          </div>
          <div class="list-content" ref="listContent">
            <ul>
              <li class="food" v-for="food in selectFoods">
                <span class="name">{{food.name}}</span>
                <div class="price">
                  <span>￥{{food.price*food.count}}</span>
                </div>
                <div class="cartcontrol-wrapper">
                  <cartcontrol :food="food"></cartcontrol>
                </div>
              </li>
            </ul>
          </div>
        </div>
      </transition>
    </div>
    <transition name="fade">
      <div class="list-mask" v-show="listShow" @click="hideMask"></div>
    </transition>
  </div>
</template>

<script>
import BScroll from "better-scroll";
import cartcontrol from "../cartcontrol/cartcontrol";
export default {
  data() {
    return {
      balls: [
        {
          show: false,
        },
        {
          show: false,
        },
        {
          show: false,
        },
        {
          show: false,
        },
        {
          show: false,
        },
      ],
      //管理小球状态
      dropBalls: [],
      //表示下面的购物车是否展开 fold表示折叠
      fold: true,
    };
  },
  props: {
    deliveryPrice: Number,
    minPrice: Number,
    selectFoods: {
      type: Array,
      default() {
        return [];
      },
    },
  },
  computed: {
    //购物车总价钱
    totalPrice() {
      let total = 0;
      this.selectFoods.forEach((food) => {
        total += food.price * food.count;
      });
      return total;
    },
    //购物车总数量
    totalCount() {
      let count = 0;
      this.selectFoods.forEach((food) => {
        count += food.count;
      });
      return count;
    },

    payDesc() {
      if (this.totalPrice === 0) {
        return `￥${this.minPrice}元起送`;
      } else if (this.totalPrice < this.minPrice) {
        let diff = this.minPrice - this.totalPrice;
        return `还差￥${diff}元起送`;
      } else {
        return "去结算";
      }
    },

    payClass() {
      if (this.totalPrice < this.minPrice) {
        return "not-enough";
      } else {
        return "enough";
      }
    },

    listShow() {
      if (!this.totalCount) {
        this.fold = true;
        return false;
      }
      let show = !this.fold;
      if (show) {
        this.$nextTick(() => {
          if (!this.scroll) {
            this.scroll = new BScroll(this.$refs.listContent, {
              click: true,
            });
          } else {
            this.scroll.refresh();
          }
        });
      }
      return show;
    },
  },

  methods: {
    drop(el) {
      for (let i = 0; i < this.balls.length; i++) {
        let ball = this.balls[i];
        if (!ball.show) {
          ball.show = true;
          ball.el = el;
          this.dropBalls.push(ball);
          return;
        }
      }
    },
    beforeEnter(el) {
      let count = this.dropBalls.length;
      // 找到显示的小球
      while (count--) {
        let ball = this.dropBalls[count];
        if (ball.show) {
          // 拿到当前“+”按钮相对于视口的位置
          let rect = ball.el.getBoundingClientRect();
          // x方向需要移动的距离
          let x = rect.left - 32;
          // y方向需要移动的距离
          let y = rect.top - window.innerHeight + 22;
          el.style.display = "";
          // 开始设置初始小球所在的位置
          el.style.webkitTransform = `translate3d(0, ${y}px, 0)`;
          el.style.transform = `translate3D(0,${y}px,0)`;
          let inner = el.getElementsByClassName("inner-hook")[0];
          inner.style.webkitTransform = `translate3d(${x}px, 0, 0)`;
          inner.style.transform = `translate3D(${x}px,0,0)`;
        }
      }
    },
    enter(el) {
      // 浏览器重绘（即某些元素的样式重新绘制）
      // 让beforeEnter的元素恢复原样
      /* eslint-disable no-unused-vars */
      let ref = el.offsetHeight;
      this.$nextTick(() => {
        el.style.webkitTransform = "translate3d(0, 0, 0)";
        el.style.transform = "translate3D(0,0,0)";
        let inner = el.getElementsByClassName("inner-hook")[0];
        inner.style.webkitTransform = "translate3d(0, 0, 0)";
        inner.style.transform = "translate3D(0,0,0)";
      });
    },
    afterEnter(el) {
      let ball = this.dropBalls.shift();
      if (ball) {
        ball.show = false;
        el.style.display = "none";
      }
    },
    // 购物车是否显示
    toggleList() {
      if (!this.totalCount) {
        return;
      }
      this.fold = !this.fold;
    },

    //清空
    empty() {
      this.selectFoods.forEach((food) => {
        food.count = 0;
      });
    },
    // 隐藏遮罩层
    hideMask() {
      this.fold = !this.fold;
    },

    //最后支付的弹窗
    pay() {
      if (this.totalPrice < this.minPrice) {
        return;
      }
      window.alert(`支付${this.totalPrice + this.deliveryPrice}元`);
    },
  },
  components: {
    cartcontrol,
  },
};
</script>

<style lang="stylus" rel="stylesheet/stylus">
@import '../../common/stylus/mixins.styl';
@import '../../common/stylus/icon.css';

.shopcart {
  position: fixed;
  bottom: 0;
  left: 0;
  z-index: 50;
  width: 100%;
  height: 48px;

  .content {
    display: flex;
    background: #141d27;

    .content-left {
      flex: 1;

      .logo-wrapper {
        display: inline-block;
        position: relative;
        top: -10px;
        margin: 0 10px 0 18px;
        padding: 6px;
        width: 56px;
        height: 56px;
        box-sizing: border-box;
        vertical-align: top;
        border-radius: 50%;
        background-color: #141d27;

        .logo {
          width: 100%;
          height: 100%;
          border-radius: 50%;
          background-color: #2b343c;
          text-align: center;

          .icon-shopping_cart {
            line-height: 44px;
            font-size: 24px;
            color: #80858a;

            &.highlight {
              color: #fff;
            }
          }

          &.highlight {
            background-color: rgb(0, 160, 220);
          }
        }

        .num {
          position: absolute;
          top: 0px;
          right: 0;
          width: 24px;
          height: 16px;
          line-height: 16px;
          text-align: center;
          border-radius: 16px;
          font-size: 9px;
          font-weight: 700;
          color: white;
          background-color: rgb(240, 20, 20);
          box-shadow: 0 4px 8px rgba(0, 0, 0, 0.4);
        }
      }

      .price {
        display: inline-block;
        vertical-align: top;
        margin-top: 12px;
        line-height: 24px;
        box-sizing: border-box;
        padding-right: 12px;
        border-right: 1px solid rgba(255, 255, 255, 0.1);
        font-size: 16px;
        font-weight: 700;
        color: rgba(255, 255, 255, 0.4);

        &.highlight {
          color: #fff;
        }
      }

      .desc {
        display: inline-block;
        vertical-align: top;
        line-height: 24px;
        margin: 12px 0 0 12px;
        color: rgba(255, 255, 255, 0.4);
        font-size: 12px;
      }
    }

    .content-right {
      flex: 0 0 105px;
      width: 105px;

      .pay {
        height: 48px;
        line-height: 48px;
        text-align: center;
        font-size: 12px;
        color: rgba(255, 255, 255, 0.4);
        background-color: #2b333b;

        &.not-enough {
          background-color: #2b333b;
        }

        &.enough {
          background-color: #00b43c;
          color: #fff;
        }
      }
    }
  }

  .ball-container {
    .ball {
      position: fixed;
      left: 32px;
      bottom: 22px;
      z-index: 200;

      .inner {
        width: 16px;
        height: 16px;
        border-radius: 50%;
        background: rgb(0, 160, 220);
      }

      &.drop-enter-active {
        transition: all 0.4s cubic-bezier(0.49, -0.29, 0.75, 0.41);

        .inner {
          transition: all 0.4s;
        }
      }
    }
  }

  .shopcart-list {
    position: absolute;
    top: 0;
    left: 0;
    transform: translate3d(0, -100%, 0);
    z-index: -1;
    width: 100%;

    &.fold-enter, &.fold-leave-to {
      transform: translate3d(0, 100%, 0);
    }

    &.fold-enter-to {
      transform: translate3d(0, -100%, 0);
    }

    &.fold-enter-active, &.fold-leave-active {
      transition: all 0.5s;
    }

    .list-header {
      line-height: 40px;
      height: 40px;
      padding: 0 18px;
      background: #f3f5f7;
      border-bottom: 1px solid rgba(7, 17, 27, 0.1);

      .title {
        float: left;
        font-size: 14px;
        color: rgb(7, 17, 27);
      }

      .empty {
        float: right;
        font-size: 12px;
        color: rgb(0, 160, 220);
      }
    }

    .list-content {
      padding: 0 18px;
      max-height: 217px;
      overflow: hidden;
      background-color: #fff;

      .food {
        position: relative;
        padding: 12px 0;
        box-sizing: border-box;
        border-1px(rgba(7, 17, 27, 0.1));

        .name {
          line-height: 24px;
          font-size: 14px;
          color: rgb(7, 17, 27);
        }

        .price {
          position: absolute;
          right: 90px;
          bottom: 12px;
          line-height: 24px;
          font-size: 14px;
          font-weight: 700;
          color: rgb(240, 20, 20);
        }

        .cartcontrol-wrapper {
          position: absolute;
          right: 0;
          bottom: 6px;
        }
      }
    }
  }
}

.list-mask {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 40;
  background: rgba(1, 17, 27, 0.6);
  backdrop-filter: blur(1px);

  &.fade-enter, &.fade-leave-to {
    opacity: 0;
  }

  &.fade-enter-active, &.fade-leave-active {
    transition: all 0.5s;
  }

  &.fade-enter-to {
    opacity: 1;
  }
}
</style>
